1. Field of the Invention
With reference to the classification of art as established in the U.S. Patent Office the present invention is found in the general Class entitled, "Liquid Purification or Separation" (Class 210) and the subclasses therein entitled, "with mechanical agitator or movable separator" (subclass 179) and the subclass in the digests entitled, "oil removal from water surface" (Digest 21).
2. Description of the Prior Art
Oil recovery systems are not new and are extensively used to pick up oil spills and the like particularly from ocean and inland waterways. Generally these oil recovery systems utilize a belt or a scraper-type apparatus and use a flotation system to separate the oil from the water or similarly contaminated liquid. In these and other known apparatus the recovery apparatus is both expensive and cumbersome and usually lacks efficiency. When a belt is used to accumulate the oil the squeezing of the oil from the belt often removes a small amount of water. The belt also requires frequent cleaning, and repair of the belt is time consuming and expensive. Even the detection of oil on water is an expensive proposition. This is particularly true in commercial installations where treated fluids are contaminated with unwanted oil as, for example, in the fluids used for grinding and the like.
In the present invention the oil recovery apparatus includes a simple frame upon which is mounted a motor which by a belt or chain drives a shaft on which is mounted a series of like disks. These disks, it has been found, are most efficient if they are made of a plastic which has a particular affinity for oil and petroleum products. Particularly effective in the pickup of oil has been polyethylene. In the embodiments to be hereinafter more fully described, these disks are preferably made of rigid polyethylene. The scrapers associated with these disks are ribbons of plastic and, as hereinafter more fully described, are Nylon strips which are bent to provide scraping edges which are pressed against the sides of the rotating disks.
In use the disks are rotated in a partly immersed condition and as they are rotated are sequentially lifted from the contaminated fluid and then are returned to an immersed condition. The scraped residue of oil removed just prior to reimmersion is fed to a conductor and then to an accumulator. As reduced to practice, the oil pickup efficiency of this disk skimmer is very good. Continued rotation of the disks in the contaminated water and the continuous scraping of the disks removes substantially all of the oil in a very short period of time.